Support for Teensy 4.0 Boards

[gannaramu]

Is your feature request related to a problem? Please describe.
I was trying to connect to the AWS IOT from my teensy 4.0 board referring to issue #17 but after successful compilation i get a warning saying:

WARNING: library SSLClient claims to run on samd, sam, tivac, stm32, esp32 architecture(s) and may be incompatible with your current board which runs on avr architecture(s).

and the Command Window I get this error message:

Attempting MQTT connection...(SSLClient)(SSL_WARN)(m_run_until): Terminating because the ssl engine closed

(SSLClient)(SSL_ERROR)(m_start_ssl): Failed to initlalize the SSL layer

(SSLClient)(SSL_ERROR)(m_print_br_error): Unknown error code: 298

Describe the solution you'd like
I wanted to check if this library supports Teensy4.0 if not are there any similar ones that support teensy 4.0 boards.

Additional context
Teensy 4.0 features an ARM Cortex-M7 processor at 600 MHz, with a NXP iMXRT1062 chip. https://www.pjrc.com/store/teensy40.html

[gannaramu]

I think I had figured out the issue I didn't initialize few things. Sorry for the Trouble.